Dynamo-electric machine with commutating-poles.



lid-854,425. 'PATENTED'MAY 21, 190?. H. R. KING.

DYNAMO ELECTRIC MACHINE WITH OOMMUTATING rows.

APPLIOATION EILED NOV. 2, 1906.

UNITED STATES PATENT OFFICE.

- HENRY It. KIN G, OF IIIN SDALE, ILLINOIS, ASSIGNOR TO WESTERN ELECTRIC QOMPANY, OFOHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

LDYNAMO-ELECTRIC MACHINE WITH COMMUTATlNG-POLES.

Patented May 21, 1907.

Application filed November 2, 1905. Serial No. 341,672.

To all mil/(JIM if; nut concern.-

.Be it known that I, HENRY R. KING, a citizen of the United States, residing at Hinsdale, in the county of Dupage and State of Illinois, have invented a certain new and useful Improvementin Dynamo-Electric Machines with Commutating-Poles, of which the following is a full, clear, concise, and exact description.

My invention relates to direct-current dynamos and motors which are provided with. compensating field windings or socalled com'mutating poles, for the purpose of overcoming the tendency to sparking at the commutator; and my object is to provide an improved means for energizing the compensating windings so that large machines may be more easily designed and constructed for accurate compensation, at a minimum cost.

For the satisfactory operation of interpole or commutating pole dynamos or motors, it is necessary that the strength of the interpole field should vary directly as the current load on thear'matui'e, in order to produce riation hasibeen produced by means of a winding for the commutating poles in series with the armature. In large machines or in machines which carry 'a' heavy current, however, the series winding must be made up of heavy copper bars, as these windings have to carry all the current passing through the" machines. As the commute/ting poles are located between the main field poles, the space for making and insulating the terminal connections is of course necessarily'restricted on this account. The expense ofhandling and fitting such heavy copper bars is also a considerable item; In accordance with my invention. these difiiculties are obviated by providing a compensating winding for the commutating po HVII'G, and connecting this winding in a circuit distinct from the main armature circuit but carrying a current which varies with the main current. I

Iwill describe my invention more particularly by reference to the accompanying drawing, which is a diagram illustrating one may take.

The diagram showsa machine having four poles,

sparkless commutation. Here'tofore thisivatained. p v cult 2 is thus caused to increase with an mes, of comparatively fine of several forms which the said inventionmain field poles N N S S, and connnutating poles P P located intermediate said main immediately over the collecting brushes; that is, facing the armature coils which are undergoing commutation. The function of these commutating poles is to compensate for the effect of armature reaction upon the field and to furnish a flux adapted to build up a reversing electrometive force in the coils which, for the time being, are short circuited by the collecting brushes, so as to prevent sparking when the segments connected to such coils leave their respective brushes.

The windings of the poles I l. are included in an energizing circuit '2 2 supplied with current from any suitable constant-potential source, the circuit being controlled by a rheostat 1' operated by a solenoid m, the Winding whereof is included in series with the main armature circuit 3 3. The source of current is indicated as a battery, but it will be "understood that this symbol is diagram matic only, and that any source of current of constant voltage may be used. In practice the energizing circuit may even be tapped off the main circuit. The rheostat shown consists of-a series of resistance coils arranged to be cut-in or out of the energizing circuit by a rotatable arm a; which is arranged to be operated by a pulley connected by a cord with the core of the solenoid m. A spring 8 attached to the other end of the cord tends to maintain the arm a in position to cut ofl all .the resistance. As the current in the main circuit increases, the increasing pull of the solenoid overcomes the pull of the spring 8 and causes the arm a to swing around and cut out the resistance until a balance is ob- The current in the energizing cirstrength of the commutating poles may be adjusted to any desired value for a given load, by adjusting the automatic regulator which controls the energizing-current without making it necessary to addvto or subtract from the number of turns of Wire upon for energizing said compensating windings,

and an automatic controlling apparatus governing said energizing means, said apparatus being responsive to changes in the current through the armature circuit of said machine.

2. ,Th combination With a direct-current" dynamo-elec'tricmachine having compensating held wmdmgs acting upon the armature coils undergomg' commutation, of a I magnet in series with the armature circuit,

and means for variably energizing said compcnsating field windings, controlled through the agency of said magnet.

, Thcombinaion with a direct-current dynamo-electric machine having compeneating field-windings acting upon the armature coils undergoing commutation, of an energizing circuit forsaid compensating windlngs, dist nct from the armature circuit, and means controlled by the variation of current flow in the armature circuit for varying the current 1n said energizing circuit.

4. The combination wlth adirect-current dynamo-electric machine having commutating poles facing the armature coils undergoing commutatlon, of an ener izing circuit for said commutatlng'poles, lstinct from the armature circuit, a rheostat controlling the flow of-current in said energizing circuit,

and a solenoid included in series in the armature circu t, the core of said solenoid be ng arranged to operate said rheostat.

In witness whereof, I, hereunto subscribe my name this 31st day of October A. D.,

HENRY R. KING. Witnesses:

JOHN G. ROBERTS, RoY T..ALL0WAY, 

